United SportsCar P2/DP prototype rules extended to end of 2016

The original plan was for the class, which will combine uprated Daytona Prototypes, LMP2 machinery and DeltaWing coupes, to run for two seasons through to the end of 2015.

It has now been decided to add a third year to what has been envisaged as a temporary formula designed to encompass cars from both Grand-Am and the American Le Mans Series, which have merged to create the USC, before a new rulebook comes into force.

The move follows a four-hour meeting over the Austin World Endurance Championship weekend between IMSA, the sanctioning body of the USC, and the Automobile Club de l'Ouest, the creator of the cost-capped P2 division and organiser of the Le Mans 24 Hours.

IMSA chairman Jim France said: "This addresses long-term on-track competitive stability, along with the economic realities of today's business climate that face everyone wanting to compete at sportscar racing's highest level."

ACO president Pierre Fillon added: "This gives the ACO and its technical partners, IMSA and the FIA, enough time to work on the possible creation of a future prototype that could replace and further revolutionise the LMP2s and the DPs in 2017 in the best possible conditions."

The announcement comes against a backdrop of delays confirming the final rules for the USC Prototype class in 2014, in particular the exact specification in which the Daytona Prototypes will run.

The first uprated DPs, which will have more downforce and slightly more power, will undergo back-to-back tests with LMP2 machinery at Sebring and Daytona in November, after which the final Balance of Performance between the two types of car will be made.

LMP2 cars competing in the USC will run in "ACO specifications", according to IMSA. It is expected that this will mean they have to race in Le Mans aero configuration to reduce downforce levels.